The overall goal of the proposed project is to contribute to reductions in HIV incidence among youth in sub- Saharan Africa. The objective of our proposed study is to advance that goal by developing, building and pilot- testing an interactive electronic game for preadolescents that will be informed by socio-behavioral and pedagogical theories, evidence-based practice, and unique formative research on youth sexual culture in sub- Saharan Africa. The game will be designed to: educate young players, ages 11-14, about sexual health and HIV/AIDS; build risk-reduction skills and related self-efficacy for prevention of HIV/STIs and unintended pregnancy; challenge harmful gender norms and HIV stigma; and foster dialogue with parents and guardians. The proposed project has the following aims: (1) to design and develop a mobile phone game for young Kenyans ages 11-14 focused on increasing age at sexual debut and condom use at first sex; (2) to pilot test the game with a sample of 60 preadolescents ages 11-14 in rural and urban Western Kenya focusing on data needed to inform a larger efficacy trial, including assessments of feasibility, acceptability, willingness, and retention. In addition, the project has the following secondary aim: to provide preliminary data on the impact of the game on mediators of sexual behavior (including knowledge, attitudes, perceived social norms, behavioral intentions, and related self-efficacy) to inform the development of an R01 proposal.